A typical walkie/rider pallet truck includes load carrying forks and a power unit having a steerable wheel. The steerable wheel is typically driven by a traction motor coupled to the steerable wheel by a transmission, also included in the power unit, and is steered by a handle mounted at the end of a movable steering arm coupled to the steerable wheel. In addition to the steerable wheel, the walkie/rider pallet truck is also supported by a pair of caster wheels or casters. The casters are preferably heavy-duty, all steel, spring loaded, articulating casters. The casters provide stability that leads to operator confidence which translates into higher levels of productivity and safety. When properly adjusted, the casters provide good lateral stability, especially when making turns. Properly adjusted casters also provide reduced drive/load/caster wheel wear. Finally, properly adjusted casters enable optimum handling, braking and traction.
To optimize and maintain truck performance, the casters must be adjusted periodically to account for tire wear and replacement. Conventionally, periodic height adjustment of the casters involves a tedious, time-consuming process of inserting or removing shims around the caster mounting bracket to obtain the correct height adjustment. Shims required for adjustment must be located and the caster mount assembly taken apart or loosened so that the required shim(s) can be inserted in or removed from the appropriate locations. Then the caster mount assembly must be reassembled. Due to the labor-intensive and cumbersome adjustment process using shims, adjustment may be delayed leading to less than optimum levels of productivity during these delayed adjustment periods. Further, if the shims are lost, the additional effort of obtaining replacement parts makes adjustment even more cumbersome.
Accordingly, there is a need for an adjustable caster assembly which does not have the problems listed above.